Well service cable sealing apparatus



Aug. 25, 1964 B. ADAMsoN ETAL WELL. sERvIcE CABLE sEALING APPARATUS 2 Sheets-Sheet l Filed April 24, 1959 FIG.

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Aug. 25, 1964 B. ADAMSON ETAL 3,145,995

wELL SERVICE CABLE SEALING APPARATUS Filed April 24, 1959 2 Sheets-Sheet 2 Fl G. 3.

' so 52a n n zo- 5 9 j M j e3 lo INVENToRs.

BLISS ADAMSON,

DANIEL H. CARTER, BY KENNETH L. MCNEMR, e4 @jd/22 Malcm ATTORNEYS.

United States Patent O 3,145,995 WELL SERVICE CABLE SEALING APPARATUS Bliss Adamson, Daniel H. Carter, and Kenneth L. Mc- Nernar, Houston, Tex., assignors to Halliburton Cornpany, .a corporation of Delaware Filed Apr. 24, 1959, Ser. No. 898,835 14 Claims. (Cl. 277-28) This invention relates to an apparatus for running tools suspended from a wire line or cable to an oil or gas well which is under high pressure.

More specically, the present invention is directed toward a fluid pressure seal about a wire line passing through a lubricator pipe or barrel which is positioned on top of a wellhead assembly.

During the operation of a well, such as an oil or gas well, it is sometimes necessary to introduce and operate within the well various tools, such as pressure or temperature recorders, flow detectors, and the like.

Such tools and instruments are ordinarily lowered into the well by means of a liexible wire line which may be an electrical conductor cable.

Because of the high pressure which may be encountered, the tools and the cable, in accordance with the conventional practice, are fed into the well through a lubricator assembly which is closed off at the upper end by a mechanical or hydraulic stuliing box. The stufiing box is designed to squeeze tightly about the lowering line or cable in order to prevent escape of the well fluids and to hold the well under control.

When the well is at very high pressure, the stufl'lng box `has to be made so tight about the line or cable that it is diliicult or impossible to lower the tool and the line into the well by their own weight.

Another factor to be considered which acts against the lowering of the tool is the well pressure itself which acts upwardly against the cross-sectional area of the cable where it passes through the stuffing box. These two factors are additional in opposition to the lowering of a wire line tool.

Several practices have been proposed to overcome these forces to allow the tool to be lowered into the well. One of these methods includes the use of weights or sinker bars which are attached to the tool to give it added Weight. in wells under high pressure, this sometimes necessitates the use of weights to such an extent that the lubricator pipe has to be undesirably long in order to accommodate them.

At times, the wire lines have been manually inserted into the wellhead by mechanical means incorporating the use of hand tools and mechanical feeders which actually pull the tool and the wire line into the well. These mechanical feeders are sometimes dangerous or time consuming and expensive.

After the line and the tool have descended to several hundered feet, it can usually be lowered by its own weight as the weight of the extended length of the wire line itself aids in overcoming the friction and pressure. However, it is the initial insertion and lowering of the wire line that the present invention is concerned with.

The main object of the present invention is to eliminate or minimize the extreme friction usually applied to the wire line by the packing in the stuffing box and to provide a substantially frictionless fluid seal about the wire line adjacent the upper end of the lubricator pipe.

The elimination of the friction of a conventional packing gland on the wire line does away with the primary force working against the lowering of the line. This also facilitates the use of less sinker bars or weights which cuts down on the overall length of the tool.

Briefly described, the present invention provides a wire line lubricator barrel which has positioned within its Patented Aug. 25, 1964 upper end a pair of spaced apart liow tubes or pressure drop members through which the wire line extends. A chamber is formed in the barrel between the how tubes.

A fluid stripping line wiper is positioned in the upper end of the barrel above the uppermost liow tube and a chamber is formed therebetween within the lubricator barrel.

The lubricator barrel is provided with ports into each of these chambers and into a chamber within the barrel below the bottom flow tube.

These ports are in respective pressure connection With a i'luid pressure system which maintains a pressure seal about the wire line in the chamber between the flow tubes. rl`he chamber between the flow tubes is maintained at a pressure which is preferably substantially equal to that of the well pressure which is admitted into the chamber below the bottom llow tube. While a pressure balance is maintained in these two chambers, the control fluid is also being circulated through the upper flow tube and into the chamber above the upper tube and thence back to the pressure system.

Other advantages of the present invention will become apparent by the following description taken in conjunction with the drawings in which:

PEG. 1 is an elevational view showing the apparatus of the present invention connected to the top of a wellhead;

FIG. 2 is a view, partly in section, of the device of FiG. 1; and

FIG. 3 is a view similar to that of FIG. 1 showing another embodiment of the present apparatus.

Referring now to the drawings, the present apparatus is illustrated as it would be installed on the upper end of the wellhead assembly generally designated as 2. The wellhead is provided with a valve 4 positioned above the wing flow lines of the wellhead so that the apparatus can be installed on and removed from the wellhead without shutting down the well or interrupting in any way its production llow, if desired. The head above the valve 4 is provided with a flange connection 6 to which is usually connected a pressure gauge or indicator.

The apparatus generally designated by the numeral 10 is connected to the wellhead 2 by means of the connection flange 6 and positioned in vertical alignment with the production tubing or pipe which is suspended in the wellhead.

The apparatus 10 consists of a lubricator pipe or barrel 12, the length of which is determined by the length of the wire line tool which is to be mn in the well. Connected into the upper end of the barrel 12 is an upwardly extending tlow tube housing 14. A second flow tube housing 16 and a liuid wiper housing 18 are also connected to the upper end of housing 14. Seen in FIG. 2, wiper housing 18 is provided with a resilient fluid wiper ring 18a. Flow tube housings 14 and 16 are each provided with an internally projecting annular shoulder 15 and 17, respectively, adjacent their lower ends.

Arranged in housing 14 and supported therein by the shoulder 1S is a metal How tube 20 held against upward movement by a set screw 21. A fluid seal is maintained between the llow tube 2li and the wall of housing 14 by sealing means such as O-rings 22.

The liow tube 2li is provided through the vertical axis thereof with a bore 23. Also provided in the ilow tube are a plurality of vertically spaced apart annular apertures or recesses 24 which are arranged about and connect with the bore 23.

A similar flow tube 26 is also supported in housing 16 by the shoulder 17 and held in place by a set screw 27. The flow tube 26 is also provided with O-rings 22, a bore 23 and apertures 24.

As can be seen, a wire line 25 which extends vertically through the entire assembly 10 also extends through 3 the bore 23 of each of the flow tubes 2f) and 26. The bore 23 is of a diameter just sufficient to allow the passage of the wire line 25.

The recesses 24, in combination with the small clearance of the bore around the wire line 25 causes a preslsure drop across the tube that decreases upwardly from the bottom of the bore 23 to the top of the tube. Such flow tubes are illustrated and described in The Composite Catalogue, 22nd edition, volume I, page 830, and manufactured by Bowen Itco, Houston, Texas. Here and after in the specification or claims such flow tubes may be variously and descriptively referred to as pressure drop ow members, pressure drop tubes, pressure drop members and pressure drop flow restriction members. In such case, such terms will describe a flow tube through which a wireline may be passed with substantially no friction while concurrently providing a substantially negligible clearance for fluid ow intermediate the wireline and the bore of such tube as described in the aforementioned Composite Catalogue.

As brought out in this description, a flow tube is a pressure drop device incorporating and alternating sequence of reduced clearance portions and turbulence chambers. The flow rate passed each reduced clearance portion is a function of the flow area of the portion and the differential pressure across the area which causes the flow. In each successive turbulence chamber, pressure energy is lost due to the turbulence imposed on the ow therein. It is thus seen that because of the turbulent loss in each successive chamber and because of the pressure drop across each successive reduced clearance portion, the pressure in each successive turbulence chamber is less than in the chamber preceding it.

Depending on the number of successive pairs of oW area or reduced clearance portion and turbulence chamber associated therewith, the total pressure drop and consequently the Volume of fluid passing through the flow tube may be reduced to an acceptable minimum. It is to be noted that the pressure drop mechanism of the flow tube functions by virtue of fluid flow. This renders it quite obvious that there will be some flow, however small, in the most excellently designed tubes if they are to function as such. Further, it is obvious that a flow tube, because of its basic design, succession of alternate restrictions and turbulent chambers, will function as a flow pressure dropping device with flow in either direction, although in a specific design, the pressure drop characteristics may be more efficient in one direction than in the other.

Positioned in housing 16 on top of the fiow tube 26 is a spacer sleeve 30 provided with an external annular recess 31 and ports 32 which communicate the recess 31 with the inside of the sleeve. Also arranged in housing 16 atop the sleeve 30 is a wire line fluid stripping rubber or Wiper 33 which is provided with a central bore 34 for the passage of the wire line 25. The wire line Wiper 33 snugly, but not tightly, engages the wire line Z and tends to prevent flow of fiuids upwardly around the wire line.

A hold-down bushing 34, the top of which abuts against an internal shoulder of wiper housing 18, holds the line wiper 33 down against the spacer sleeve 30.

As shown, the wire line 25 extends through the top of the assembly 12 through the Wiper ring 13a and passes over a wire line sheave 35 which is pivotally mounted on and adjacent the top of the assembly. The line 25 is wound on a reel (not shown) which may be mounted on a service truck or the like. A chamber 40 is formed in wiper housing 18 by the wiper 18a and the line Wiper 33. The housing 18 is provided with a threaded port 41 which fiuidly communicates with the chamber 40.

A chamber 42 is formed by the spacer sleeve 30, the bottom of the line wiper 33 and the -top of the flow tube 26. A threaded port 43 formed in the wall of housing 16 fluidly communicates with the chamber 42 by way of recess 31 and ports 32. A threaded port 14a provided in the wall of housing 14 communicates a chamber 44 defined by the inner wall of housing 14 and the flow tubes 2f) and 26.

The lubricator barrel 12 is provided with a threaded port 4S which connects with the chamber 46 formed by the inner wall of the barrel 12 and the flow tube 20.

Chambers 4t) and 42 will hereinafter be referred to as low pressure chambers and chambers 44 and 46 will be referred to as high pressure chambers. Chambers 40 and 42 are connected into the top of a fluid reservoir or tank 5f) by means of return lines or conduits 51 and 52 which are connected into ports 41 and 43.

The intake or suction of pump 53 is connected to the bottom of the reservoir 5t) by a conduit 54. The discharge of the pump 53 is connected by a conduit 55 to the inlet of a three-way valve 56 having a diaphragm control actuator, for example. One outlet of the valve 56 connects back into the reservoir tank 50 by way of a conduit 57 which acts as a fluid return or recycle line. The other outlet of the valve 56 is connected to the high pressure chamber 44 by a conduit S8.

A differential pressure controller 59, air operated for example, is connected to the high pressure chamber 44 by means of a conduit 6i) which connects into the conduit 58. The controller 59 is also connected with the high pressure chamber 46 by way of a conduit 61 which is connected into port 45. A pressure signal connection conduit 62 is connected between the outlet of pressure controller 59 and the diaphragm housing of three-Way valve 56. The pressure controller 59 is connected to a gas or air pressure source (not shown) by means of a conduit 63.

The pressure controller 59 detects any variation of the pressure differential between the high pressure chambers 44 and .46 and controls the diaphragm action of threeway valve 56 by bleeding out or admitting air to the diaphragm housing. A suitable pressure controller such as described is manufactured by the Barton Instrument Corp., of Monterey Park, California, and is illustrated and described in their Bulletin No. 237-1 of Ocotber 1957. Other types of controllers may be used, if desired.

The embodiment shown in FIG. 3 is the same as that of FIGS. l and 2 except for a slight modification of the control means. In this embodiment, the three-way valve is eliminated and the discharge of a pump 53a is connected directly into the chamber 44 by way of the conduit 58a. 'Ihe differential pressure controller 59, as in FIG. l, is connected between chamber 46 and conduit 58a. A control connection pressure line 62a is connected between the outlet of pressure controller 59 and a pump control unit 70 arranged on the pump 53a. In this embodiment, variations in the pressure differential between the high pressure chambers 44 and 46 is detected by the pressure controller 59 which, in turn, transmits a corresponding control signal to the pump control unit 70, whereby the speed of operation of the pump 53a is maintained as required. In this embodiment, there is no need for a recycle line such as 57, as shown in FIG. l.

Operation Before the assembly 10 is connected to the wellhead 12, the valve 4 is closed and the pressure gauge 0r bull plug which is positioned on top of the valve is removed.

The well tool, such as a logging tool 64, which is connected to the lower end of line 25 is pulled up completely within the lubricator barrel 12. The assembly 10 is then picked up and connected to the wellhead 2 by means of the connection 6. The conduits, as described, are connected to the ports 41, 43, 44a, and 45.

The tank or reservoir 50 is filled with a control Huid which may be any clean fluid free of foreign matter, such as water or oil, for example.

The pump 53 is energized and starts pumping the control fluid from the tank S0, through valve 56, recycle line 57 and back into the tank.

As the pressure in chambers 46 and 44 are equal, that is atmospheric before valve 4 is opened, the valve 56 will `continue to cause fluid to circulate through the recycle line 57 and back to tank 50.

With the pump in operation, the wellhead valve 4 is opened and well pressure is admitted to chamber 46 of the barrel l2. At this time the pressure diferential between the chambers 46 and 44 becomes maximum. This differential pressure is immediately detected by the pressure differential controller 59 and a control signal pressure is transmitted to the diaphragm housing of the three-way valve 56 by way of line 62.

Upon actuation of the valve 56, the passage of fluid through recycle line 57 is closed off and the control fluid is then pumped into chamber 44 by way of line 53. This circulation continues and the pressure within chamber 44 is increased until it is substantially equal (or at a preselected diferential with) the pressure in chamber 46 which is the well pressure.

This selectable differential pressure permits great exibility in operation and control in that when the selection results in a pressure in chamber 44 in excess of the well pressure, the lower flow tube functions in reverse and control fluid is passed into the well bore thus completely avoiding any production of well fluid. Of course, the upper flow tube functions normally in any event and drops the pressure of the high pressure of the control fluid in chamber 44 to atmospheric pressure at the other end of ow tube 26. In this control situation, it is obvious that only the control fluid is produced from the upper end of the upper flow tube.

The control fluid pumped into chamber 44 is forced upwardly through the passage 23 of the pressure drop member 26 and into the chamber 42. As previously described, the member 26 casues a differential pressure drop, the pressure in the chamber 42 then being substantially lower than that in chamber 44.

The control fluid entering the chamber 42 is returned to the reservoir tank 5t) by way of port 43 and conduits 52 and 51. As the pressure within chamber 42 is held at a minimum, there is no need for a high frictional pressure packing around the line 25 above this chamber.

Some control tluid which may be carried through the wiper member 33 by the line 25 will be wiped from the line by the wiper ring 18a. This fluid will be contained in chamber 4t) and be drained back to the tank 50 through conduit 51.

Instead of using a high pressure stuflng box as used in conventional lubricators, the present apparatus affords the use of the wiper member 33 which only contacts the line 25 enough to wipe it clean of fluids and to retain the low pressure tluids through member 26 between bore 23 and cable 25.

It may be desirable at times to have the pressure differential controller set so that the chamber 44 can be maintained at a pressure slightly above that of the well pressure found in chamber 46 and thus assure absolutely no production of well fluid. Such times are, for example, when a well is productive of dangerous substances such as highly combustible gas or radioactively contaminated oil or gas, any production of which would be quite hazardous. A liquid level indicator may be positioned on the reservoir tank 50 whereby the operator can visually determine whether the control fluid is being pumped into the well or if the well liuids are entering the control system.

' Pressure gauges may also be installed on the conduits 58 and 61 to give the operator means for detecting the pressures existing within the chambers 46 and 44.

In the embodiment of FIG. 3, the operation is similar to that of FIG. 1 with the exception that the control iluids are pumped into the chamber 44 at a rate responsive to the pressure control signals transmitted by the pressure differential controller 59 to the pump control unit 70 which determines the speed of the pumps operation or llow rate through the pump.

It may at times be desirable to pressurize the chambers 44 and 46 with control fluid before opening the wellhead Valve 4. In wells which produce some sand and other foreign matter it is not desirable to let these fluids enter the control system, that is mix with and contaminate the control uid. For the most efficient operation, it is better to maintain the control fluid as clean as possible at all times.

In removing the tool 64 and the wire line 25 from the well bore, the pressure control between the chambers 44 and 46 is maintained in the same manner.

As can be seen in the foregoing description, the present invention provides a simple pressure balance mechanism which affords a frictionless fluid seal about a wire line run in a well under pressure. The present invention affords a fluid seal around a Wire line whereby the use of a mechanical or hydraulic stuffing box can be eliminated.

Additional weights, such as sinker bars, may be used on the lighter tools which are sometimes very buoyant but for the heavier tools these weights can be eliminated. Minimizing the use of extra weights affords the use of shorter lubricator barrels which is very advantageous.

Having fully described and illustrated the apparatus of the present invention and its operation, what is claimed l. Apparatus for running tools suspended from a wire line into a well under pressure, comprising in combination: a lubricator barrel adapted to be connected to a wellhead in axial alignment with the bore of said wellhead, a tluid stripping wiper member in the upper end of said barrel, upper and lower vertically spaced apart pressure drop ow members arranged in said barrel below said wiper member, said wire line adapted to extend through said barrel, said pressure drop ow members and said wiper member, a rst chamber formed in said barrel below said lower pressure drop member, a second chamber formed in said barrel between said pressure drop members, a third chamber formed in said barrel between said upper pressure drop member and said fluid stripping wiper member, a pump having tiud intake and discharge connections, a pressure conduit connecting said discharge connection to said second chamber, a fluid reservoir tank connected to the intake connection of said pump, a uid return conduit connected between said third chamber and said reservoir, a differential pressure controller connected between said first chamber and said pressure conduit, and means connected between said pressure controller and said pump for controlling the operation of said pump.

2. Apparatus for running tools suspended from a wire line into a well under pressure, comprising in combination: a lubricator barrel adapted to be connected to a wellhead in axial alignment with the bore of said wellhead, a fluid stripping wiper member in the upper end of said barrel, upper and lower vertically spaced apart pressure drop ilow members arranged in said barrel below said wiper member, said wire line adapted to extend through said barrel, said pressure drop ow members and said wiper member, a first chamber formed in said barrel below said lower pressure drop member, a second chamber formed in said barrel between said pressure drop members, a third chamber formed in said barrel between said upper pressure drop member and said fluid stripping wiper member, means connected between said first and said second chambers for detecting pressure differentials between said chambers, means connected to said second chamber and said detecting means for pressurizing said second chamber in response to said detected differentials, and a tluid return conduit connected between said third chamber and a reservoir tank.

3. Apparatus for running tools suspended from a wire line into a well under pressure, comprising in combination: a lubricator barrel adapted to be connected to a wellhead in axialalignrnent with the bore of said wellhead, a fluid stripping wiper member in the upper end of said barrel, upper and lower vertically spaced apart pressure drop flow members arranged in said barrel below said wiper member, said Wire line adapted to extend through said barrel, said pressure drop flow members and said wiper member, a first chamber formed in said barrel below said lower pressure drop member, a second chamber formed in said barrel between said pressure drop members, a third chamber formed in said barrel between said upper pressure drop member and said wiper member, differential pressure indicating means connected between said first and said second chambers, means connected into said second chamber and said indicating means for introducing fluid under pressure into said second chamber responsive to the indicated pressure differential, said barrel provided with a port adjacent said third chamber for draining fluid from said third chamber.

4. Apparatus for running tools suspended on a wire line in a well under pressure, comprising in combination: a lubricator barrel adapted to be connected to the wellhead in axial alignment with the bore of said wellhead, a wiper member in the upper end of said barrel disposed about said wire line, upper and lower vertically spaced apart pressure drop flow members arranged in said barrel, a packing means disposed intermediate said wiper member and said upper flow member, said wire line being adapted to extend through said barrel and said flow members, a first chamber formed in said barrel below said lower flow member, a second chamber formed in said barrel between said flow members, a third chamber formed in said barrel between said upper flow member and said wiper member, a fourth chamber formed in said barrel between said wiper and said packing means, a recycle valve having an inlet and two outlets, a pressure conduit connected between said second chamber and one outlet of said recycle valve, a pumping means having an intake and a discharge, the inlet of said valve connected to a discharge of a pumping means, a fluid reservoir connected into an intake of said pumping means, a recycle conduit connected between another outlet of said valve and said fluid reservoir, a fluid return conduit connected between said third chamber and said fluid reservoir, a pressure differential responsive control means connected between said pressure conduit and said first chamber, and a control actuator for said valve fluidly connected to said control means.

5. The apparatus for running tools suspended from a wireline into a well under pressure which includes: a tool barrel adapted to be connected in axial relation with a wellhead, a fluid stripping member disposed in the upper end of said barrel, an upper and a lower pressure drop flow restriction member disposed within said barrel below said stripping member, said barrel, stripping member and restriction members being adapted to pass the wire line therethrough, said lower restriction member and said barrel defining a first fluid chamber within said barrel, said lower restriction member and said upper restriction member defining a second fluid chamber within said barrel, said upper restriction member and said stripping member dening a third fluid chamber within said barrel, a fluid pumping means, including a control actuator therefor, in fluid connection to said second chamber, a pressure differential responsive control means connected in fluid connection between said first chamber and said second chamber, a fluid reservoir in fluid connection with said third chamber and the intake of said pumping means, said pressure control means being in connection with said control actuator of said pumping means for varying the fluid flow through said pumping means to said second chamber in response to the pressure differential between said first and said second chambers to maintain the pressures in said first and second chambers at a preselected differential pressure.

6. The apparatus for running tools suspended from a wire line into a well under pressure which includes: a tool barrel adapted to be connected in axial relation with a wellhead, an upper and a lower pressure drop flow restriction member disposed within said barrel, said barrel and restriction members being adapted to pass the wire line therethrough, said lower restriction member and said barrel defining a first fluid chamber within said barrel, said lower restriction member and said upper restriction member defining a second fluid chamber within said barrel, said upper restriction member and barrel defining a third fluid chamber within said barrel, a controllable recycle valve having an inlet, a plurality of outlets and including a control actuator, a `fluid pumping means, having an intake and an outlet having the outlet thereof in fluid connection through the inlet and one outlet of said controllable recycle valve to said second chamber, a pressure differential responsive control means connected in fluid connection between said first chamber and said second chamber, a fluid reservoir in fluid connection with said third chamber .and the intake of said pumping means and with a second outlet of said valve, said pressure control means being in connection with said control actuator of said valve for diverting fluid flow through said valve to said second chamber in response to the pressure differential between said first and said second chambers to maintain the pressures in said first and second chambers at a preselected differential pressure.

7. The apparatus for running tools suspended from a wire line into a well under pressure which includes: a tool barrel adapted to be connected in axial relation with a wellhead, an upper and a lower pressure drop flow restriction member disposed within said barrel, said lbarrel and restriction members being adapted to pass the wire line therethrough, said lower restriction member and said barrel defining a first fluid chamber within said barrel, said lower restriction member and said upper restriction member defining a second fluid chamber within said barrel, said upper restriction member and barrel defining a third fluid chamber within said barrel, a controllable recycle valve having an inlet, a plurality of 4outlets and including a control actuator, a fluid pumping means, including an intake and a discharge, having said discharge in fluid connection through the inlet and one outlet of said controllable recycle valve to said second chamber, a pressure responsive control means connected in fluid connection with said first and second chambers, a fluid reservoir in fluid connection with said third chamber and the intake of `said pumping means and with a second outlet of said valve, said pressure control means being in connection with said control actuator of said valve for diverting fluid flow through said valve to said second chamber in response to the pressure occurring in said first chamber to maintain a preselected differential pressure between said first and second chambers.

8. Apparatus for running tools suspended from a wire line in a well which is under pressure, comprising in combination: a tubular barrel, upper and lower spaced apart pressure drop tubes in the upper portion of said barrel dening a first chamber therebetween in said barrel, a wiper ring in said barrel above said upper pressure drop tube, said barrel defining a second chamber therein between said Wiper ring and said upper pressure drop member, said ybarrel defining a third chamber below said lower pressure drop member, means connected to said third chamber and said first chamber for providing indications of the pressure differential between said first and third chambers, means connected into said first chamber for pressurizing said first chamber in response to said indications, said `barrel defining a port adjacent said second chamber, means on the lower end of said barrel for connecting said barrel to a wellhead,

9. The apparatus for running tools suspended from a wire line into a Well under pressure which includes: a tool barrel adapted to be connected in axial relation with a wellhead, a fluid stripping member disposed in the upper end of said barrel, an upper and a lower pressure drop flow restriction member disposed within said Ibarrel below said shipper member, said barrel, `said stripping member, and restriction members being adapted to pass the wireline therethrough, said lower restriction member and said barrel defining a first fiuid chamber within said barrel, said lower restriction member and said upper restriction member defining a second fiuid chamber within said barrel, said upper restriction member and said stripping member defining a third fluid chamber within said barrel, -a controllable recycle valve having an inlet and a plurality of outlets and including a control actuator, a fiuid pumping means, including an intake connection and a discharge, having said discharge in fluid connection through the inlet and one outlet of said controllable recycle valve to said second chamber, a pressure differential responsive control means in fluid connection between said Kfirst chamber and said second chamber, a fluid reservoir in fluid connection with said third chamber and said intake connection of said pumping means land with a second outlet of ISaid valve, said pressure control means being in connection with said control actuator of said Valve for positioning said valve to divert fluid fiow through said valve to said second chamber in response to the pressure differential between said first and said second chambers to maintain the pressures in said first and second chambers at Ia preselected difierential pressure.

10. The apparatus for running tools suspended from a wire line into a well under pressure which includes: a tool barrel adapted to be connected in axial relation with a wellhead, an upper and a lower pressure drop ow restriction member disposed within said barrel, said barrel and restriction members being adapted to pass the wire line therethrough, said lower restriction member and said barrel defining a first fluid chamber within said barrel, said lower restriction member and said upper restriction member defining a second fluid chamber within said barrel, said upper restriction member and said barrel defining a third fluid chamber within said barrel, a fluid pumping means, including a control actuator and having an intake and a discharge, with said discharge thereof in fiuid connection to said second chamber, a pressure differential responsive control means connected in fiuid connection between said first chamber and said second chamber, a fluid reservoir in fiuid connection with said third chamber and the intake of said pumping means, said pressure control means being in connection with said control actuator of said pumping means for varying the fiuid ow through said pumping means to said second chamber in response to the pressure differential between said first and said second chambers to maintain the pressures in said first and second chambers at a preselected differential pressure.

11. The apparatus for running tools suspended from a wire line into a well under pressure which includes: a tool barrel adapted to be connected in axial relation with a wellhead, an upper and a lower pressure drop fiow restriction member disposed within said barrel, said barrel and restriction members being adapted to pass the wire line therethrough, said lower restriction member and said barrel defining a first ffuid chamber within said barrel, said lower restriction member and said upper restriction member defining a second fluid chamber within said barrel, said upper restriction member and said barrel defining a third fiuid chamber within said barrel, a fiuid pumping means, including a control actuator and having an intake and a discharge, with said discharge thereof in fiuid connection to said second chamber, a pressure re sponsive control means connected in fluid connection to said first chamber, a uid reservoir in fluid connection with said third chamber and the intake of said pumping means, said pressure control means being in connection with said control actuator of said pumping means for varying the fiuid flow through said pumping means to said second chamber in response to the pressure occurring in said first chamber to maintain a preselected differential pressure between said first and second chambers.

12. Apparatus of the type described, comprising, a tubular barrel and first and second fiow tubes respectively provided With bores for passing a wireline therethru, said flow tubes disposed in spaced apart relation within said barrel and defining with said barrel a first chamber between said tubes, a second chamber above said first tube, and a third chamber below said second tube, said barrel and said bores of said flow tubes being of a size to pass a wireline of a given size with running clearance and with substantially no mechanical friction, a pressure controller connected with said first chamber and said third chamber, a variable fluid pressure source connected with said first chamber, said pressure source being connected with and controlled by said pressure controller, and means on the lower end of said barrel for connecting said barrel to the well head, the arrangement being such that fiuid fiow under pressure is provided to said first chamber in response to a pressure communicated to said third chamber from said well head.

13. Apparatus of the type described, comprising a tubular barrel and first and second ow tubes respectively provided with bores for passing a wireline therethru, said fiow tubes disposed in spaced apart relation within said barrel and defining with said barrel a first chamber between said tubes, a second chamber above said first tube, and a third chamber below said second tube, said barrel and said boresv of said flow tubes being of a size to pass a wireline of a given size with running clearance and with substantially no mechanical friction, a differential pressure controller connected with said first chamber and said third chamber, a variable fluid pressure source connected with said first chamber, said pressure source being connected with and controlled by said pressure controller, and means on the lower end of said barrel for connecting said barrel to the well head, the arrangement being such that fiuid fiow under pressure is provided to said first chamber in response to a prescribed differential pressure occurring between said third chamber and said first chamber.

14. Apparatus of the type described, comprising a tubular barrel and first and second fiow tubes respectively provided with bores for passing a wireline therethru, said ow tubes disposed in spaced apart relation within said barrel and defining with said barrel a first chamber between said tubes, a second chamber above said first tube, and a third chamber below said second tube, said barrel and said flow bores of said tubes being of a size to pass a wireline of given size with running clearance and with substantially no mechanical friction, a differential pressure controller connected with said first chamber and said third chamber, a variable fluid pressure source connected with said first chamber, a fiuid reservoir connected between said second chamber and said pressure source, said pressure source being connected with and controlled by said pressure controller, and means on the lower end of said barrel for connecting said barrel to the well head, the arrangement being such that fluid pressure is provided to said first chamber for flow to said second chamber in response to a pressure occurring between said third chamber and said first chamber.

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12. APPARATUS OF THE TYPE DESCRIBED, COMPRISING, A TUBULAR BARREL AND FIRST AND SECOND FLOW TUBES RESPECTIVELY PROVIDED WITH BORES FOR PASSING A WIRELINE THERETHRU, SAID FLOW TUBES DISPOSED IN SPACED APART RELATION WITHIN SAID BARREL AND DEFINING WITH SAID BARREL A FIRST CHAMBER BETWEEN SAID TUBES, A SECOND CHAMBER ABOVE SAID FIRST TUBE, AND A THIRD CHAMBER BELOW SAID SECOND TUBE, SAID BARREL AND SAID BORES OF SAID FLOW TUBES BEING OF A SIZE TO PASS A WIRELINE OF A GIVEN SIZE WITH RUNNING CLEARANCE AND WITH SUBSTANTIALLY NO MECHANICAL FRICTION, A PRESSURE CONTROLLER 